Dan Henderson came out on top the first time he squared off with former champion Mauricio Rua in November 2011 at UFC 139, but barely. Eleven years Rua’s senior, the two-time title challenger bore the brunt of a late-round burnout when the two swung for the fences early in the fight. Rua’s comeback threatened to finish him, but Henderson made it to the bell to win three of five rounds on the judges’ scorecards.

It was Henderson’s first fight back in the UFC after a 15-month stint in the now-defunct Strikeforce promotion, and the win would have gotten him a title shot were it not for a knee injury that was the catalyst for the canceled debacle of UFC 151.

The rematch is being billed as the second part of the best fight in UFC history, a tag which is outdated now with so many white-knuckle headliners being contested in the past 12 months.

Henderson, though, is going into the rematch not only with his eyes wide open, but with the knowledge that another loss could spell disaster for his UFC career. While he recently re-upped with the promotion with a six-fight contract, a loss to Rua would signal his fourth consecutive defeat in the octagon. Rua recently resuscitated his UFC career with a bonus-winning knockout of James Te Huna this past December, but another loss to Henderson might dash any chance of getting a title shot, if a chance even exists at light heavyweight after his decimation at the hands of current champ Jon Jones.

In reality, Henderson (29-11 MMA, 6-5 UFC) and Rua (22-8 MMA, 6-6 UFC) probably are better suited at middleweight, but a shared dislike of weight-cutting and an easy-sell rematch brings them back together.

1. Who will you be without TRT?

It’s not the question Henderson needs to ask himself right now, but it’s one we’re bound to think about as we watch the ex-PRIDE champ take to the cage. On Sunday, Henderson fights for the last time with permission to use testosterone-replacement therapy, though it’s hard to imagine the stuff will ever leave the sport.

Henderson is the current posterboy for older-than-40 fighters. But in competition years, he is darn near a septuagenarian, and if you’re looking for a counter-balance to the argument that TRT made Vitor Belfort testosto-riffic, “Hendo” might be your guy. Against Belfort, he looked old, and against younger and faster fighters such as Rashad Evans and Lyoto Machida, a deficit in speed compounded his relatively predictable attack. Henderson likes to corner opponents and land his powerful right hand, of course. But testosterone doesn’t change the fact that he hasn’t switched things up in quite some time, and if you prepare for his most dangerous weapons, you’ll probably have a good night.

Henderson might be the last public TRT user, but he seems destined to get off it as he got on it in 2007 – without much fanfare. Others might not be the same.

2. Play it again, Sam

Henderson recently went on the record that his first fight with Rua wasn’t all that special despite the fanfare it had received. Interesting opinion, but then again, have you ever seen “Hendo” get excited about, well, anything? For those of us on the outside of the cage, it was a shot of energy toward the end of that year that the injury bug ravaged. Henderson vs. Rua might not be the best bout in UFC history, but it’s definitely in the top five, and if they somehow can find the magic a second time, as did Michael Chandler and Eddie Alvarez, you’d be silly to miss it.

3. Mutations

Vitor Belfort protege and capoeira master Cezar Ferreira (7-2 MMA, 3-0 UFC) is an out-of-the-box star from the UFC’s first Brazilian season of “The Ultimate Fighter,” and he could one day take his teacher’s place as a homegrown headliner. But the middleweight gets a tough challenge in C.B. Dollaway (13-5 MMA, 7-5 UFC), whose wrestling and submission skills could be too much, too soon for the young fighter. Ferreira is a sizable favorite, and his striking is unpredictable enough to where he could catch the “TUF” veteran. It probably won’t be easy, though.

4. ‘TUF’ you, ‘TUF’ me

Winners of the international versions of “TUF” face a tougher uphill road than earlier counterparts. The promotion’s roster is bigger than ever, and they don’t get the airtime that stateside winners do. Hardcores know lightweight Thiago Santos (12-3 MMA, 1-0 UFC) won “TUF: Brazil 2″ as an injury replacement, and Norman Parke (19-2 MMA, 3-0 UFC) won “TUF: Smashes.” Parke, though, has a big head start in octagon experience, and is now with the renowned Alliance training center in San Diego. The Irish fighter is on a roll, having won three straight to Santos’ one in the octagon, so Brazilians could be in for a downer.

5. ‘The Iron Hillbilly’

You worry about Fabio Maldonado’s brain when he steps into the octagon, but you also worry about those who stand across from him. The Brazilian light-heavyweight takes too many punches for his own good, though his brick fists are a thing of beauty to watch. His latest opponent, Gian Villante (11-4 MMA, 1-1 UFC), recently told MMAjunkie Radio he’s comfortable standing with Maldonado (20-6 MMA, 3-3 UFC). We’ll see when he takes his first shot.

6. Bend it like ‘Beckan’

Lightweight Mairbek Taisumov (21-4 MMA, 1-0 UFC) didn’t blow anyone’s hair back in his UFC debut earlier this year against Tae Hyun Bang, but maybe that was just octagon jitters. A short-notice injury replacement for Gleison Tibau gives the Austrian, nicknamed “Beckan,” a chance to redeem himself against Michel Prazeres (17-1 MMA, 1-1 UFC), who saved his job in a UFC career that’s been similarly so-so. It’s time for somebody to make an impression, or go home.

7. Friday the 13th for Jason?

Another breakout Brazilian star, “TUF: Brazil 1″ winner Rony Jason (13-4 MMA, 3-1 UFC), was poised to break into the top 10 before being on the wrong end of a quick knockout from Jeremy Stephens. Now forced to reset, his return opponent, featherweight Steven Siler (23-11 MMA, 5-2 UFC), might be a little less heavy-handed, but presents no less a scrappy threat. The threat, however, is somewhat diminished on the mat, as standout Dennis Bermudez revealed again in his recent defeat over Siler. So count on Jason to take a slightly more conservative approach, but don’t count this out as a fun scrap.

8. Minor threat

So featherweight Diego Brandao (18-9 MMA, 4-2 UFC) went a little nuts. The last time we saw him, he was making terroristic threats (the legal definition of what happens when you say you’re going to stab someone) and then getting knocked out. Now that that’s out of his system, he’s in a back-against-wall situation against Will Chope (19-6 MMA, 1-0 UFC). It’s a significant step down in competition, from a resume a standpoint, but Chope towers over Brandao, and if he plays it smart (which he admits is tough), this might be an even match.

9. Flyweight eliminator

Flyweight Jussier Formiga (15-3 MMA, 1-2 UFC) came into the UFC as a top-ranked 125-pound fighter in the promotion’s new small-man division. But after a trio of uneven performance, he’s closer to fighting for his job than a title against Scott Jorgensen (14-8 MMA, 3-4 UFC), whose reinvention at flyweight from bantamweight also hasn’t been smooth sailing. It’s do-or-die time.

10. Submission surprise

Welterweight Kenny Robertson (12-3 MMA, 1-3 UFC) stumbled in his most recent bout against Sean Pierson, but here’s hoping a fight against striking specialist Thiago Perpetuo (9-2 MMA, 1-1 UFC) gives him another opportunity to pull off another whacky submission like the one against Brock Jardine at UFC 157. That was cool. And besides, at 1-3 in the octagon, he needs to impress.

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